1. Field of the Invention
This invention relates generally to containers and related packaging, and more specifically to an improved internal cover for liquid containers and the like.
2. Description of the Prior Art
Liquid paints and coatings, such as oil-base and water-base paints, are in widespread use, and are typically packaged in buckets or cylindrical metal containers bearing "friction-plug" or other type lids enabling the resealing of the containers after initial use. However, even after such resealing, the unused paint left in the container is exposed to the air-filled void in the container, causing evaporation of the volatile components and oxidation of the non-volatile components of the remaining liquid. These processes result in the hardening of the exposed paint surface (i.e., formation of a "skin") and thickening of the remaining liquid. In addition, miscellaneous dirt and debris can fall into the container when replacing the container lid or during subsequent removal, further contaminating the remaining paint.
Several prior art devices have been developed in an attempt to to remedy this problem. Most such devices comprise a "floating" internal lid designed to rest upon the surface of the remaining liquid, thereby acting as a barrier and sealing the liquid from the air-filled void. However, even these devices permit some evaporation and/or oxidation, resulting in the undesired thickening and skin formation.